[M-TT37] New Developments in Earth Science Explored by Dense GNSS Observation Networks

[MTT37-P06] Development of dense GNSS atmospheric delay database around Japan

*Mikiko Fujita¹, Fumihiko Akazawa¹, Shinya Kouketsu¹ (1.Japan Agency for Marine-Earth Science and Technology)

Keywords:GNSS, Tropospheric delay, Precipitable water vapor

The GNSS observation network in Japan is operated by the Geospatial Information Authority of Japan (GSI) (electronic reference points, over 1,300 points nationwide), and the amount of atmospheric delay or precipitable water estimated at some observation points is assimilated into the numerical forecast model. On the other hand, since November 2019, SoftBank Corp. has started to operate its own GNSS observation network of ultra-multipoint (over 3,300 points nationwide) to upgrade its positioning services. This study constructs the analysis system that performs daily precise single-positioning (PPP) using over 4,000 GNSS observation data points. The analyzed GNSS atmospheric delays by PPP will be archived in the database. It might have functions that allow us to search for statistically significant extreme value cases by comparing them with long-term data from GSI's network. The presentation will include examples of applications, such as detecting statistically significant weather disturbance events by precipitable water vapor converted from atmospheric delay.
The data used in this study for post-processing analysis of SoftBank's original GNSS sites were provided by SoftBank Corporation and ALES Corporation through the framework of the “Consortium to utilize the original dense GNSS network by SoftBank for a wide area of earth science”.